One of the things you need to do when looking for a server to run Asterisk on is figure out how much bandwidth you need for the number of concurrent calls you’re expecting to have. A great tool for this can be found here – http://www.asteriskguru.com/tools/bandwidth_calculator.php Just set the codec you’re going to be using (check with your VOIP provider – g.711/ulaw is usual and the highest quality), the connection type (usually SIP or IAX2 with Asterisk) and the number of concurrent calls. It will then display the bandwidth required for that many calls. One thing to watch out for…